Electrical attachment



Feb. 21, 1939. P. E. HAMILTON 2,147,790

ELECTRICAL ATTACHMENT Q Filed July 31, 1936 Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE} 2,141,190 ELECTRICAL ATTACHMENT rump E. Hamilton, Beaver Falls, Pa. Application July a1, 1936, Serial No. 93,710

Claims.

receptacle is attached are struck by lightning,

l5 sparks are discharged from the slots in the receptacle. Also, particularly in certain industrial plants where the atmosphere is heavily laden with dust and other foreign matter, the slots in the receptacles become filled up and clogged Eli by such foreign matter, thus rendering proper contact dimcult and presenting the possibility of short circuiting.

And. finally, considerable dimculty has been experienced in the previously used receptacles as by virtue of the fact. that, after a period of use, and due to the wear of either the receptacle or the plug, the jacks of the plug are not securely held within the receptacle.

An object of this invention is to overcome the above objections inherent in the prior devices.

Another object of this invention is to provide a receptacle having features which prevent the possible electrical shocking of persons-using the same. Yet another object of this invention is to provide a receptacle affording at all times a tight I fit with a plug, and having means to prevent the entrance of dust and other foreign matter to the slots.

-A further object of .this invention isto providea receptacle having the foregoing characteristics and yet simple and economical in construction and requiring only slight changes from the present conventional type of receptacle.

J With these and other objects in view, which -may be incident to my improvements, the'invention consists in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements comprising my invention may be varied in construction, proportions and arrangement,

without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly as understood, I have shown in the accompanying (Cl. 173-343) This invention relates to-electrical fixtures,

drawing means for carrying the same into practical efiect without limiting the. improvements in their useful applications to the particular constructions which, for the purpose of explanation, have been made the subject of illustration. 5

In the drawing:

Figure l is a frontal elevation of one embodiment of a receptacle constructed in accordance with my invention. Figure 2 is aside elevation of the receptacle 10 shown in Figure 1.

Figure 3 is a sectional view along the line 3-3 of Figure 31.. g

Figure 4 is a sectional view taken along the line ll\of Figure 1. iii

Figure 5 is a cross sectional view-along the line tt of Figure 3. c

Figure 6 is a view in perspective of the receptacle and the cooperating plug in the process of'insertion in the receptacle.- ht

Referring more particularly to Figures 1 and 2, the receptacle is composed of a cylindrical body portion i, which may be of vulcanized rubher or anyother appropriate insulating material.

At the front end of the body portion i an annu- 25 lar flange 2 is provided, and at the opposite end a metallic and threaded ring 3 iits around the body portion. The ring 3 is provided with an inturned skirt 4 which lies against the rear of the body member. 36

The front of the body member i is cut away to form a recess 5, the upper portion of the wall of such recess having a slope as at 6. The recess 5 is preferably circular, but in any event the sloping portion-6 is circular, for a purpose later to be described.

Channels I and 8, diametrically opposed, extend from the base of the recess 5 to the rearof the body portion. These channelsare adapted to receive the lacks of a plug, and there are posi- 40 tioned in the slots contact members 9 and II, respectively. The contact members 9 and Ii are engaged by the plug Jacks when the plug is in operative position.

While I, have disclosed an embodiment com- 45 prising a receptacle which is adapted to be screwed into a permanent socket, it will of course be appreciated that the invention may readily take the form of a permanent receptacle which does not require a socket. However, when using 50 the receptacle in association with a socket, the

contact 9 is in electrical communication with-the center contact in a socket, and the contact II is in communication with the side Contact of a socket. As best shown in Figure 3, a disc I2, is

with a slot l9 through which contact 9 extends.

A metallic circular and raised cap I fits over the disc l2 and over an extension of the contact 9 which projects from the slot IS. A screw i5 is adapted to hold the skirt 6, contact 9, disc l2 and plate H in assembled position upon the body member I. As indicated at I6, the contact 9 is continued and is provided with an aperture through which the screw i6 passes. In view of the contact between the contact 9, plate I and screw IE, it will be observed that contact 9 is in communication with the center contact of the socket in which my receptacle is threaded.

Contact II is bent around the rear of the body member and thence downwardly as at I! to rest within a recess l9 formed in the side of the body member. It will be noted that the threaded ring 9 engages the portion i1 of contact H, and likewise engages the side contact of the socket to thereby place contact II in communication with the side contact of .the socket.

A central recess l9, preferably square or rectangular in cross section, extends from the base of the recess 5. Recess I9 is provided with shoulders 2| beyond which is a restricted portion 22 extending to the rear of the body portion. There is adapted to fit within the recess 19, and to abut against the shoulders 2!, a. block 23 having a cross section corresponding to that of recess l9.

The block 23 is thereby held against rotation. 01 course, in lieu of a recess and block angular in cross section, the recess and block may be round and a set screw or other suitable holding means provided. A threaded recess 24 is provided in the end of the block adjacent the rear of the body member, and the screw [5 is enthreaded therein.

A circular disc 25 is adapted to fit in recess 5 and to rest upon the sloping portion 6 of the recess wall. This permits of ready rotation of the disc 25 with respect to the body portion of the receptacle. Diametrically opposed slots 26 extend through the disc. 25. A helical spring 21 has one end embedded in the block 23 and the opposite end embedded in the rear of disc 25, by vulcanizing or any other suitable means. This spring of course resiliently opposes any rotation of the disc 25 with respect to the body portion l of the receptacle.

The block 29 and disc 25 are so assembled in the receptacle that the slots 26 are 90 out of alignment with the channels 1 and 8. The spring 21, while resiliently opposing rotation of disc 25, nevertheless does permit rotation of the disc in either direction until the slots 26 register with channels 1 and 8. The strength of the spring 21 may be varied, but is preferably sufiiciently strong for the disc 25 to resist rotation except by the jacks of a plug, and in any event the spring is of course sumciently strong to return the disc to a position where the slots are out of' register with the channels 1 and 9.

The operation of my invention is of course ob- .vious. As shown in Figure 6, a plug 29 provided with contacting jacks 29 is used in the operation of my device. .As stated, theslots 26 of disc 25 are normally out of register with channels 1 and 9 of the receptacle, and the jacks 29 are initially inserted in the slots 26. The plug 28 is then rotated, in either direction, until slots 26 come into register with channels 1 and 9, and then the plug is further inserted untiltheplug 28 is in engagement with the flange 2 of the receptacle.

When in this position, the jacks 29 are in engagement with contacts 9 and II to close the circuit. It will be noted that the plug is securely held in operative position, not only by the resiliency of contacts 9 and I I but also by a clamping action on the jacks set up by the disc 25 and spring 21.

When it is desired to disconnect the plug, it is withdrawn 'from the receptacle, whereupon the disc 25 returns to its inoperative position, where the slots 26 are out of register with channels 1v and 8.

It will be appreciated that my invention provides a safety device for receptacles, preventing accidental or careless contact with the electrical contacts in the receptacle.- By providing a spring 21 of sufilcient strength, access to the contacts 9 and Ii can be secured only by the use of a plug, at all other times the channels 1 and 8 being closed. Accidental shocksare thereby prevented.

It will also be observed that this closing of the channels 1 and 8, except when the receptacle is in use, prevents the admission of dust and other foreign matter to the channels. Likewise, it will be noted that by my invention a plug is held more securely in operative position than has heretofore been possible. I 7 1 An outstanding feature of my invention is the simplicity and economy of construction, and it will be appreciated that only slight changes are necessary in order to convert the conventional type of receptacle to an embodiment of my invention.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not confine myself to the precise details of construction herein set forth, by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims.

I claim:

1. An electrical receptacle comprising a body portion, a pair of channels extending therethrough, an electrical contact member in each channel, a third centrally disposed channel, an anchoring member secured in said third channel, a shutter member having a pair of slots adapted to register with the first two mentioned) channels, and resilient means having. its ends embedded in said shutter and in said anchoring member, said resilient means being adapted to secure the shutter to the body portion and to normally hold the shutter slots out of register with the channels.

2. An electrical receptacle comprising a body portion, a pair of diametrically opposed channels extending therethrough, an electrical contact member in each channel, a third centrally disposed channel, an anchoring member secured in said third channel and held against rotation therein, a shutter member having a pair of slots adapted to register with the pair of channels, and a helical spring having one and embedded in said anchoring member and the other end embedded in the shutter, said spring adapted to secure the shutter to the body portion and to normally hold the shutter slots out of register with the channels.

3. An electrical receptacle comprising a body portion, a pair of channels extending therethrough, an electric contact member in each of said channels, a centrally disposed and shoul- 'dered channel extending through the body poru tion, a block adapted to rest against said shbulder, a shutter member having a pair of slots adapted to register with the channels, a helical spring extending from the block to the shutter and adapted to secure the shutter to the body portion and to normally hold the shutter slots out of register with the channels, a closure membar for the end of the body portion opposite the shutter, and means for maintaining said closure member upon the body portion, which means are also adapted to hold the block in engagement with the shoulders of the central channel.

4. An electrical receptacle comprising a body portion, a pair of channels extending therethrough, an electrical contact member in each channel, a third centrally disposed channel, an anchoring member secured in said third channel, a shutter member having a pair of slots adapted to register with the first two mentioned channels, and resilient means having its ends embedded in said shutter and in said anchoring member to secure the shutter to the body portion and to normally hold the shutter slots out of register with the channels.

5. An electrical apparatus comprising a body portion, a pair of channels extending therethrough, an electrical contact member in each channel, a third centrally disposed channel, a block secured in said third channel, a shutter member having a pair of slots adapted to register with the first two mentioned channels, and a resilient member having its ends embedded in said shutter and in said block to secure the shutter to the body portion and to normally hold the shutter slots out of register with the channels. PHILIP E. HAMILTON. 

